KR101336531B1 - Method and apparatus for reducing combiner loss in a multi-sector, omni-base station - Google Patents

Abstract

Omni-wireless base stations with multiple sector antenna units use frequency division of sector signals to achieve increased coverage or capacity at reduced cost. Each sector antenna unit has an antenna that receives a carrier signal related to the antenna frequency in an available frequency band. At least one antenna unit has an associated frequency converter that converts the carrier signal received by the antenna unit from the antenna frequency to several individual frequencies. Although each sector receives the same carrier signal, the output carrier signal associated with each sector is in several frequency bands. The combiner combines the antenna unit carrier signals at various frequencies to produce a composite signal for communicating with the omni-wireless base station. Since the combined antenna unit signals are at several frequencies, they do not interfere more than they are at the same antenna frequency, resulting in less signal loss and degradation at the combiner. The carrier signal is then restored at the base station transceiver from several individual frequencies to an intermediate frequency for further processing.

Omni-Wireless Base Station, Synthetic Signal, Antenna Unit Carrier Signal, Frequency Converter

Description

METHOD AND APPARATUS FOR REDUCING COMBINER LOSS IN A MULTI-SECTOR, OMNI-BASE STATION}

The present invention relates to a multi-sector wireless base station. In one non-limiting example application, the techniques described herein can be used in an omni base station coupled to a multi-sector antenna system.

An omni-base station is a base station configured to use an omni-antenna, and a sector base station is configured to use a plurality of (two or more) sector antennas. 1A shows a single cell area for a base station (BS) with an omni-antenna. The omni-antenna radiates 360 degrees to cover the entire cell area. 1B shows a single cell area for a base station (BS) with three sector antennas. Three sector base stations have a common sector configuration, but several sectors may be used. In this case, the cell area is divided into three, and each sector antenna has a narrow beam (relative to omni-antenna) that radiates to cover its sector area of about 120 degrees.

Base station antennas are often fixed in high locations, such as towers, poles, tops or sides of buildings, to enhance coverage and provide good possibilities for direct radio signal propagation paths. 2A shows a base station unit 14 located at the base of the tower 12. The antenna 10 is mounted on top of the tower 12 and coupled to the base station transceiver via a feed cable 16, preferably coaxial cable or the like. The received signal causes signal loss across feeder 16, with higher towers 12 the longer the feeder and the greater the loss. To eliminate this signal loss in the feeder, a tower-mounted amplifier (TMA) can be used to amplify the received signal before being sent through the feeder to the base station unit. 2B shows the TMA 18 mounted on top of the tower 12 proximate the antenna 10. Tower mounted units are often referred to as mast head amplifiers. The term tower mounted amplifier (TMA) is generally used herein to include any device that performs this pre-feeder amplification function.

3 shows a simplified block diagram of an omni-base station 20. The antenna 10 is coupled to the duplex filter 21 of the TMA 18 including a receive (Rx) filter 22 and a transmit (Tx) filter 24. The duplex filter separates the Tx and Rx signals from each other, allowing transmission and reception on the same antenna. The transmit filter 24 is directly coupled to the feeder 16, and the receive filter 22 is coupled to the feeder 16 through a low noise amplifier (LNA) 26. The feeder 16 couples to a base station 14 that also includes a duplex filter 28 that includes a receive (Rx) filter 30 and a transmit (Tx) filter 32. The transmit filter 32 is coupled to the transceiver 36, and the receive filter 30 is coupled to the transceiver 36 via a low noise amplifier 34.

Antenna diversity can be used to improve reception (or transmission) of transmitted wireless signals. There are several kinds of diversity such as temporal diversity, spatial diversity and combinations thereof. The promising diversity scheme uses a time / space coded signal and is called multiple input multiple output diversity (MIMO). Spatial diversity reduces the effect of fading received wireless signals. The antenna diversity system includes at least two antennas arranged spaced apart from each other. In the case of receive diversity, the received signal is received on two or more antennas. The Rx signal from the diversity antenna undergoes diversity processing to obtain an enhanced signal. Diversity processing includes, for example, selecting the strongest antenna signal or adding a signal and further processing the resulting signal. In the case of transmit diversity, a transmit (Tx) signal is transmitted on two or more transmit antennas to which the transmitter is connected. The antenna of the diversity arrangement is called a diversity antenna. In a diversity arrangement, the feeder and its associated antenna may be referred to as a diversity branch or simply a branch.

4 shows an example of an omni-base station 14 with diversity. Two diversity antennas 10a, 10b are coupled to corresponding TMAs 18a, 18b. Each TMA is coupled by a power supply 16a, 16b corresponding to a low noise amplifier unit 42a, 42b and a corresponding duplex filter at base station 14. Two duplex filters and LNAs 42a and 42b are coupled to a single transceiver 36.

In contrast to a single transceiver used at an omni-base station, a sector base station as shown in FIG. 5 has a separate transceiver for each sector. Three sectors are maintained in each sector with its own antennas 10 ₁ , 10 ₂ , 10 ₃ . Each antenna 10 ₁ , 10 ₂ , 10 ₃ is coupled to a corresponding sector TMA 18 ₁ , 18 ₂ , 18 ₃ . Three feeders 16 ₁ , 16 ₂ , 16 _{3 couple} individual TMAs 18 ₁ , 18 ₂ , 18 ₃ to corresponding base station units 14 ₁ , 14 ₂ , 14 ₃ . Each base station unit 14 ₁ , 14 ₂ , 14 ₃ has a corresponding duplex filter and low noise amplifying units 42 ₁ , 42 ₂ , 42 ₃ . Sector base stations offer more coverage than omni-base stations, but require more money and power.

Although omni-base stations are less complex and less expensive than sector base stations, they also provide less coverage, so the operator must install more omni-base stations to cover a particular geographic area than when sector base stations are installed. In response, a multi-sector omni-base station is introduced in which the omni-base station is coupled to a multi-sector antenna system. In fact, in the example where three sector antenna systems are used with omni-base stations, the three sector antenna systems add a signal gain of about 7-8 dB.

An example of three base stations 60 is shown in FIG. 6A. Three sectors are maintained in each sector with its own antennas 10 ₁ , 10 ₂ , 10 ₃ . Each antenna 10 ₁ , 10 ₂ , 10 ₃ is coupled to a corresponding sector TMA 18 ₁ , 18 ₂ , 18 ₃ . Three feeders 16 ₁ , 16 ₂ , 16 _{3 couple} individual TMAs 18 ₁ , 18 ₂ , 18 ₃ to base station 14. Base station 14 comprises three duplex filters and a low noise amplifier unit, generally labeled 42, to which three transceivers 36 are coupled. Since feed cables, duplex filters and transceivers are expensive (more than when diversity is used in each sector), splitters / combiners are used so that only one feeder is needed. 6B shows that the signals received from the three sectors 1, 2, 3 are all combined onto a splitter / combiner 44 on one feed cable 16. In the transmission direction, the transmission signal is divided into three identical signals (with low power) and provided to the TMA of each sector. Another gain of a multi-sector omni-base station is the ability to "tilt", eg, downtilt, one or more sector antennas. Tilting is not an option for omni antennas.

However, the feeder cost savings obtained by using splitters / combiners are offset by substantial power losses in the combiners. Indeed, in the three sector example described above, the 7-8 dB gain achieved by using a three sector antenna system is offset by a 5 dB loss in the combiner. This loss is due to the interference between the three sector received signals caused when they are combined at the combiner. This frequency overlap interference significantly reduces the signal-to-interference ratio of the sector signal received at the base station transceiver. Power is split into three different sectors in the splitter for downlink transmission with less than 5 dB (ie 1/3) of power for each sector. One method that can be used to handle downlink transmission loss is to simply increase the base station transmission power. However, substantially increasing the mobile station transmit power level across the board is not an option in the uplink because the transmit power of the mobile station is generally tightly controlled and limited.

Omni-wireless base stations with multiple sector antenna units use frequency division of sector signals to achieve increased coverage or capacity at reduced cost. Each sector antenna unit is coupled to an antenna that receives carrier signals related to the antenna frequency band in the usable frequency band. The term "frequency band" includes a single frequency as well as a range of frequencies. The frequency converter in the antenna unit converts the carrier signal received by one of the plurality of antenna units from its antenna frequency to another individual frequency. The narrowband filter filters out some of the available frequency bands of interest. One or more frequency converters may be used. The combiner combines the carrier signals associated with each of the plurality of antenna units to produce a composite signal for communicating with the omni-radio base station. At least two carrier signals associated with the multiple antenna units and combined at the combiner are received by accommodating circuit elements at the omni-base station at various frequencies.

Based on the implementation, the number of the plurality of sector antenna units including the corresponding frequency converter may be less than or equal to the number of the plurality of sector antenna units. The combiner combines the carrier signals associated with each of the plurality of antenna units to produce a composite signal in which all of the combined carrier signals are related to or at several frequencies in which only a portion of the carrier signal is to be combined.

In one non-limiting embodiment, each frequency converter comprises a first local oscillator L0 that provides a first LO frequency signal, the first mixed frequency using a first LO frequency signal and a sector carrier signal. Convert one of these to an intermediate frequency (IF) signal. The narrowband filter filters the frequency conversion output. The second local oscillator provides a second LO frequency signal corresponding to an individual frequency band, and the second mixer mixes the second LO frequency signal and the intermediate frequency signal to generate a frequency converted output. Narrowband filters or wideband filters (depending on the selectivity in the IF filter) filter the frequency conversion output into individual frequency bands. Alternatively, IF conversion does not need to be performed if there is a narrowband filter with sufficient selectivity after conversion.

The feeder coupled to the combiner transports the composite signal to the base station unit. The omni-base station accommodating the circuit elements extracts respective carrier signals corresponding to the plurality of sector antenna units from the synthesized signal. The omni-base station containing the circuit elements includes one or more base station mixers. Each base station mixer frequency converts the corresponding one of the individual carrier signals related to the other frequency to an intermediate frequency for further processing. In three non-limiting example examples, at least two base station mixers each receive several local oscillator signals that extract several sector carrier signals.

In one exemplary implementation, one or more frequency converters are included in corresponding one or more multiple antenna units. Alternatively, one or more frequency converters are included in the combiner. If there are multiple individual multiple frequency bands used as a result of the frequency conversion, these individual multiple frequency bands are distributed over the usable frequency bands. Preferably, these individual frequency bands are evenly distributed over the available frequency bands.

Diversity reception can be used. For example, each sector may include a first diversity antenna unit and a second diversity antenna unit. A non-limiting example diversity implementation includes a first combiner that combines carrier signals associated with each first diversity antenna unit to generate a first composite signal for communication with an omni-radio base station, each second A second combiner for combining a carrier signal associated with the diversity antenna unit to generate a second composite signal for communication with the omni-wireless base station. The first feeder transports the first synthesized signal to the base station unit, and the second feeder transports the second synthesized signal to the base station unit. The base station unit extracts respective diversity carrier signals corresponding to the plurality of sector antenna units from the first and second diversity synthesized signals using one or more base station mixers. Each base station mixer frequency converts the corresponding one of the individual diversity carrier signals related to the various frequencies to an intermediate frequency for further processing.

In another non-limiting example diversity implementation, a single combiner is used to combine the carrier signals associated with each of the first and second diversity antenna units to produce a composite signal for communicating with an omni-radio base station. The splitter / combiner couples the sectors to one feed cable. Thereafter, the single feeder transports the synthesized signal comprising two frequencies for each sector to the base station receiving circuit element, which corresponds to several diversity sector antenna units from the synthesized signal using one or more base station mixers. Each diversity carrier signal is extracted. Each base station mixer frequency converts the corresponding one individual diversity carrier signal relating to several frequencies to intermediate frequencies for further processing.

The frequency of transforming a signal received on at least one sector antenna unit used with an omni-wireless base station allows for a combiner loss that is commonly encountered when sector signals are combined without frequency conversion. In a combined three sector omni-radio base station, if all signals are at different frequencies, about 5 dB power loss is avoided at the combiner. The method can be used with less feed cables without incurring substantial losses in the combiner. Indeed, only a single feed cable needs to be used in non-diversity as well as in diversity implementations. More efficient multi-sector omni-base stations are commercially attractive because the coverage and / or capacity for the omni-base stations can be increased using sector antennas. Indeed, existing omni-base stations can be easily upgraded to full coverage base stations using sector receive antennas and frequency conversion prior to transmission to base station transceivers via a combination and feed cable. Another advantage is that power consumption is reduced because of using less hardware.

1A shows a single cell area for a base station (BS) with an omni-antenna;

1B shows a single cell area for a base station (BS) with three sector antennas;

2A shows a base station tower;

2B illustrates a base station tower with a tower-mounted amplifier (TMA);

3 is a simplified block diagram of an omni-base station;

4 shows an example of an omni-base station with diversity;

5 illustrates an example of a sector base station;

6A shows an example of three sector base stations;

FIG. 6B shows an example of a three sector omni-base station using a splitter / combiner and one feed cable; FIG.

7 is a functional block diagram of a non-limiting exemplary embodiment of a multi-sector, omni-base station with reduced combiner loss;

8A is a diagram of usable frequency bands separated into subbands at the antenna for the 850 MHz band, for example;

FIG. 8B is a diagram showing an example in which several sector signals are frequency converted from a frequency band usable on a feeder to a corresponding sub band; FIG.

9A is a diagram of a PCS frequency band separated into a 5 MHz subband;

Fig. 9B is a diagram showing an example in which three various sector signals are frequency converted from a PCS frequency band to a corresponding sub band on a power feeder;

FIG. 10 is a flowchart outlining a non-limiting exemplary procedure for reducing combiner loss at a multi-sector, omni-base station; FIG.

11 is a functional block diagram of another non-limiting exemplary embodiment of a multi-sector, omni-base station with reduced combiner loss.

12 is a functional block diagram of another non-limiting exemplary embodiment of a multi-sector, omni-base station with reduced combiner loss;

13A and 13B are functional block diagrams of another non-limiting exemplary embodiment of a multi-sector, omni-base station with reduced combiner loss with diversity; And

14 is a functional block diagram of another non-limiting exemplary embodiment of a multi-sector, omni-base station with reduced combiner loss with diversity using only a single feeder.

In the following description, for purposes of explanation and not for purposes of limitation, details, such as specific nodes, functional entities, techniques, protocols, standards, and the like, are described for the purpose of understanding the described techniques. It will be apparent to those skilled in the art that other embodiments may be practiced from the details that follow. For example, while the exemplary embodiment is described in terms of several sector omni-wireless base stations, the disclosed techniques may also be applied to other types of multi-antenna devices and may be applied in indoor as well as indoor applications. In other instances, well known details of methods, devices, techniques, and the like are omitted so as not to obscure the description with unnecessary details. Individual functional blocks are shown in the figures. Those skilled in the art will appreciate that the functionality of these blocks may use discrete hardware circuitry, use software programs and data relating to a suitably programmed microprocessor or general purpose computer, and / or use an application specific semiconductor (ASIC) and / or one or more digital signal processors (DSPs). Will be implemented using).

7 is a functional block diagram of a non-limiting exemplary embodiment of a multi-sector, omni-base station 70 with reduced combiner loss. The term "multiple" means that two or more, in this non-limiting example, three sectors S ₁ , S ₂ , S ₃ have their own antennas 10 ₁ , 10 ₂ , 10 ₃ . It is understood to mean that each sector is kept. Each antenna 10 ₁ , 10 ₂ , 10 ₃ is coupled to a corresponding sector antenna unit called in a non-limiting example, such as a tower mounted amplifier (TMA) 18 ₁ , 18 ₂ , 18 ₃ . Three TMAs 18 ₁ , 18 ₂ , 18 ₃ are connected to a splitter / mixer 62 so that only one feeder 16 includes a receive filter 30 and a low noise amplifier 34. And a TMA received signal to the omni-base station 14 comprising a single duplex filter. For simplicity, the transmission path is omitted. Each TMA includes a receive (Rx) filter 72 ₁ , 72 ₂ , 72 ₃ coupled to its respective antenna 10 ₁ , 10 ₂ , 10 ₃ .

Each receive filter 72 ₁ , 72 ₂ , 72 ₃ is coupled to a separate amplifier 74 ₁ , 74 ₂ , 74 ₃ , and the amplified output is, for example, local oscillator 78 ₁ , 78 ₂ , 78 ₃ . And a corresponding mixer 76 ₁ , 76 ₂ , 76 _{3 that} is mixed with the frequency converted signal generated by the same. In one non-limiting example, the frequency converted signal is different for each sector so that each sector signal is converted to several frequencies. The output of each mixer is filtered using individual narrowband (NB) or bandpass filters (80 ₁ , 80 ₂ , 80 ₃ ) centered on separate frequencies, so that noise as well as interference from other parts of the available band Remove the mixed product.

Although each sector signal is shown as a transformed frequency just for the sake of explanation, one or more sector signals may not be the transformed frequency. Preferably, each sector signal is at several frequencies before it is combined and transported to the omni-wireless base station transceiver unit. In these three sector examples, the two sector signals may be frequencies converted to several frequencies, but the third frequency is not a converted frequency. In this case, the three sector signals are also at various frequencies. Several frequencies are identified by f ₁ , f ₂ and f ₃ . In a less optimal example implementation, some sector signals are at several frequencies, but two or more sector signals remain at the same frequency. This implementation is less optimal because the signals interfere at the same frequency and the signal-to-noise ratio is reduced at the combiner.

Although not necessary, it may be desirable to frequency convert the combined signal to several frequencies, such as lower frequencies, before transmitting the combined signal through the feeder 16. For example, converting the combined signal at a very low frequency can minimize losses at feeder 16 and therefore also reduce noise.

In the base station 14, the power supply 16 connects to the duplex filter unit 42, in which only the reception filter 30 and the LNA 34 are shown. The duplex filter unit 42 is connected to an omni-base station receiver, only a portion of which is shown and includes a mixer 82 ₁ , 82 ₂ , 82 ₃ . In general, a multi-sector, omni-base station receiver will use one mixer in the steps followed by the narrowband filter to downconvert the received wireless signal. However, in this example, because each sector received signal is at several frequencies, three different local oscillator signals L0 ₁ , LO ₂ , L0 ₃ are mixed with the synthesized signal from combiner 62. Local oscillators 84 ₁ , 84 ₂ , 84 ₃ provide three different local oscillator signals L0 ₁ , LO ₂ , L0 ₃ . Each output is then filtered at narrowband intermediate frequency (IF) filters 86 ₁ , 86 ₂ , 86 ₃ to generate corresponding sector received signals Rx ₁ , Rx ₂ , Rx ₃ . These sector received signals Rx ₁ , Rx ₂ , Rx ₃ then prepare for further processing.

To help explain the frequency conversion, an example is now described with reference to FIGS. 8A and 8B. 8A is a diagram of usable antenna frequency bands separated into subbands A-E. However, subband B is the frequency band used by the omni-radio base station. Fig. 8B is a diagram showing an example in which all three multi-sector signals received in the subband B used are the frequencies converted from the frequency bands available for feeding to the corresponding subbands: subband A, C, E) are used. Although one of the sector signals need not be the converted frequency and can be maintained in the subband B used, in this case it is not preferable because no guard band will be present. Having a guard band reduces the chance of interference between sector carrier signals.

A practical example in the Personal Communication Services (PCS) band will be described with reference to FIGS. 9A and 9B. 9A shows the PCS from 1850-1910 MHz separated into twelve 5 MHz subbands (A ₁ , A ₂ , A ₃ , D, B ₁ , B ₂ , B ₃ , E, F, C ₁ , C ₂ , C ₃ ) Diagram of antenna frequencies for frequency bands. The subbands used by the wireless base station are from 1865-1870 MHz to the 5 MHz D band. For the three sector example, all three multi-sector signals received in the subband D used are the frequencies converted from the usable frequency bands to the corresponding feeder subband frequencies, in this embodiment, in FIG. 9B. As shown are A ₁ , B ₃ and C ₃ . However, one of the sector signals need not be the converted frequency and can be maintained in the subband D used, and there will also be a guard band separating the three sector signals.

In this non-limiting example, receive filters 721, 722, 723 pass through a 60 MHz frequency band available from 1860-1910 MHz, respectively. However, the base station uses only the 5 MHz "D" subband from 1865-1870 MHz. The first sector received signal is the NB filter ₁ pass frequency between 1850-1855 MHz and the frequency shifted to the A ₁ subband using the LO ₁ signal set at 15 MHz (1865-1850 = 15). The second sector received signal is the frequency shifted to the B ₃ subband using the NB filter ₂ pass frequency between 1880-1885 MHz and the LO ₂ signal set at 15 MHz (1880-1865 = 15). The third sector received signal is the frequency shifted to C ₃ using the NB Filter 3 pass frequency between 1905-1910 MHz and the LO ₃ signal set at 40 MHz (1905-1865 = 40).

A frequency multiplexed signal carrying three sector carriers in three different frequency bands, A ₁ (1850-1855), B ₃ (1880- 1885), and C ₃ (1905-1910) via feeder 16 is omni- Processed by the base station receiving circuitry. The received signal is filtered using a receive filter 30 that passes through the 60 MHz wide PCS band from 1850-1910 MHz. After amplifying the signal filtered in the LNA (34), the amplified received signal is transmitted to the three mixer (82 _1, 82 _2, 82 _3), each of the converted before it is sent through the feed electricity 16 frequency For this sector one is in this example. The purpose of the illustrated receiving circuit element is to convert each sector signal into the same intermediate frequency (IF) signal. IF downconversion simplifies filtering and facilitates baseband processing. To achieve conversion to an IF of 200 MHz, LO ₁ is set to 1652.5 MHz; LO ₂ is set to 1682.5 MHz; LO ₃ is set to 1707.5 MHz. In this non-limiting example, the 200 MHz output from mixer 821 is then filtered by each of the three 5 MHz NB filters 861,862,863 to frequency from 197.5-202.5 MHz (centered around 200 MHz IF). Pass it through.

10 is a flow diagram that outlines a non-limiting example of reducing combiner loss in a multi-sector, omni-base station. In step S1, each of the several sector antenna units receives a carrier signal related to the antenna frequency in the usable frequency band. The carrier signal received by one of the several antenna units is a frequency converted from the antenna frequency to a separate individual frequency from the narrowband filtering and antenna frequency bands (step S2). Carrier signals associated with each of the various antenna units are combined to generate a composite signal for communication with the omni-radio base station (step S3). At least two of the carrier signals associated with the various antenna units and combined at the combiner are at different frequencies. The synthesized signal is transported through the feeder to the base station unit (step S4). Each carrier signal is extracted from the synthesized signal comprising a frequency for converting at least one carrier signal relating to several frequencies to intermediate frequencies for further processing (step S5).

11 is a functional block diagram of another non-limiting exemplary embodiment of a multi-sector, omni-base station 90 with reduced combiner loss. This embodiment is similar to FIG. 7 except that frequency conversion is performed at combiner 63 instead of antenna unit. Alternatively, three antennas may be coupled to one TMA unit including three receive filters, three LNAs, three frequency converters, three narrowband filters and one combiner coupled to one feeder. .

12 shows a multi-sector, omni-base station 92 with reduced combiner loss, where the frequency conversion includes intermediate frequency (IF) conversion, narrowband filtering and conversion to RF in the approximately usable frequency band, but on different frequencies. Is a functional block diagram of another non-limiting exemplary embodiment. The reason why IF conversion can be used first before performing frequency conversion to separate the sector signal at frequency before combining is: (a) IF-filter is more efficient than RF-filter, and (b) IF down-conversion and Up-conversion is a known technique with better than RF-RF conversion, and (c) feeder frequencies include those that can be located where desired in the usable frequency band. At the base station, the local oscillator and mixer down-convert several frequencies to the IF for further processing.

13A and 13B are functional block diagrams of another non-limiting exemplary embodiment of a multi-sector, omni-base station 94 with reduced combiner loss with diversity. Each sector TMA 18 ₁ , 18 ₂ , 18 ₃ includes two diversity receive branches A, B, although more than one diversity branch can be used if desired. For simplicity, the transmission path is omitted. Each TMA has individual first antennas 10 _1A , 10 _2A , 10 as well as receive (Rx) filters 72 _1B , 72 _2B , 72 _3B coupled to individual second antennas 10 _1B , 10 _2B , 10 _3B . _3A ) receive (Rx) filters 72 _1A , 72 _2A , 72 _3A .

Each receive filter in the first diversity branch is coupled to an individual amplifier 74 _1A , 74 _2A , 74 _3A , and each receive filter in the second diversity branch is an individual amplifier 74 _1B , 74 _2B , 74 _3B ). Is coupled to. The amplified output for each first branch is coupled to a corresponding first mixer 76 _1A , 76 _2A , 76 _3A , generated by, for example, a separate sector local oscillator 78 ₁ , 78 ₂ , 78 ₃ . The amplified output for each second branch is coupled to the corresponding second mixer 76 _1B , 76 _2B , 76 _3B , where, for example, by the same individual sector local oscillator 78 ₁ , 78 ₂ , 78 ₃ . It is mixed with the generated frequency converted signal. In this non-limiting example the frequency converted signal is different for each signal such that the two diversity signals for each sector are converted to a different frequency than the other sector signal. The output of each mixer in the first diversity branch is filtered using individual narrowband (NB) or bandpass filters (80 _1A , 80 _2A , 80 _3A ) centered on the individual frequencies to reduce noise and interference in the available bands. As well as other mixed products. Similarly, the output of each mixer in the second diversity branch is filtered using individual narrowband (NB) or bandpass filters (80 _1B , 80 _2B , 80 _3B ) centered on the individual frequencies to filter out other mixed products. Remove it. Two narrowband filters in each sector are centered on the same individual frequency.

The "A" diversity branch output from each sector is combined at the first combiner 62A, and the "B" diversity branch output from each sector is combined at the second combiner 62B. In this way, only one feeder 16A is needed to combine the TMA received signal from the first diversity branch to the omni-base station 14 at several frequencies f _1A , f _2A , f _3A . Only feeder 16B is needed to couple the TMA received signal from the second diversity branch to the omni-base station 14 at various frequencies f _1B , f _2B , f _3B .

The omni-base station unit 14 replaces the first duplex filter and low noise amplifier unit 42A for the first feeder 16A and the second duplex filter and low noise amplifier unit 42B for the first feeder 16B. Include. The output from the first duplex filter and low noise amplifier unit 42A is connected to the mixers 82 _1A , 82 _2A , 82 _3A and the output from the second duplex filter and low noise amplifier unit 42B is the mixers 82 _1B , 82 _2B. , 82 _3B ). The output from a single local oscillator (L0 ₁ ) 84 ₁ is mixed with the input to mixers 82 _1A and 82 _2A to allow IF or other desired frequencies (e.g., homodyne) for separate filtering at 86 _1A and 86 _1B . The signal is converted into a baseband such as (homodyne) to generate diversity reception signals Rx _1A and Rx _1B from sector 1. The output from a single local oscillator (LO ₂ ) 84 ₂ is mixed with the input to mixers 82 _2A and 82 _2B to convert the signal to IF or other desired frequency for separate filtering at 86 _2A and 86 _2B Generate diversity reception signals Rx _2A and Rx _2B from 2). The output from a single local oscillator (LO ₃ ) 8 8 ₃ is mixed with the inputs to mixers 823A, 823B and combined with IF or other desired frequencies (eg, homodyne) for separate filtering at 86 _3A and 86 _3B . The signals are converted to the same baseband to generate diversity reception signals Rx _3A and Rx _3B from sector 3.

14 is a functional block diagram of another non-limiting exemplary embodiment of a multi-sector, omni-base station 96 with reduced combiner losses with divers using only a single feeder 16. In this non-limiting example, there are three sectors S1-S3, each sector comprising two diversity antennas 10A, 10B. Each diversity antenna in this example has its own TMA (individual one of 18 _1A- 18 _3B ) which generates an output signal at several frequencies (individual one (f _1A -f _3B )). These six different frequency carriers f _1A -f _3B are combined in a single combiner 62 and transported to the omni-base station unit 14 via a single feeder 16. Since each sector diversity signal is at several frequencies in this non-limiting example, they do not interfere directly at the combiner 62 or the feeder 16. Compared to the exemplary embodiments of Figures 13A-13B, one less coupler and one fewer feeder are used, which saves cost. Based on the size of the available frequency band assigned to the base station, there may be some or no guard band between each of the six TMA signals f _1A- f _3B , although there are disadvantages. As a result, interference may be added, so the signal-to-noise ratio is reduced. In addition, only a single duplex accepts filter 30, and LNA 34 is needed at base station unit 14, as compared to the two in the exemplary embodiment of FIGS. 13A-13B. On the other hand, six (compared to three) multiple local oscillators (84 _1A- 84 _3B ) are needed to provide six different local oscillator signals (LO _1A- LO _3B ) to individual mixers (82 _1A -82 _3B ). do.

Although various embodiments have been shown and described in detail, the claims are not limited to any particular embodiment or example. The above description should not be read as to imply that any particular element, step, range, or function is essential to be included in the scope of the claims. The scope of the patented subject matter is limited only by the claims. The scope of legal protection is defined by the words mentioned in the allowed claims and their equivalents. No claim is intended to carry out paragraph 6 of 35 USC § 112 unless the term “means to” is used.

Claims (40)

An apparatus for use in a multi-sector omni-radio base station providing wireless communication coverage for a geographic site area divided into multiple sectors, A plurality of sector antenna units, each sector antenna unit providing wireless communication coverage to a particular sector that is different from a sector covered by another of the plurality of sector antenna units, each of the plurality of sector antenna units transmitting downlink transmissions. A plurality of sector antenna units having an antenna for transmitting a signal and for receiving a carrier signal associated with a receiving antenna frequency in an available frequency band; A frequency converter for frequency converting the carrier signal received by one of the plurality of sector antenna units from the receive antenna frequency to a respective frequency different from the receive antenna frequency; And Receives a downlink signal at full transmit power, and splits the downlink signal into a plurality of identical split signals transmitted by the plurality of sector antenna units, each of the split signals being of a received downlink signal. Each portion of the total transmit power, and each of the sector antenna units transmits each split signal at the same base station transmit frequency to each portion of the total transmit power, Up a carrier signal received from a plurality of different sectors by a corresponding one of the plurality of sector antenna units to generate a composite signal comprising information received from the plurality of different sectors for communicating with the multi-sector omni-radio base station. A splitter / coupler that couples in the link direction, And at least two of the carrier signals associated with the plurality of sector antenna units and combined in the combiner are at different frequencies. The method according to claim 1, And wherein the number of multiple sector antenna units with corresponding frequency converters is less than the number of sector antenna units. The method according to claim 1, And the number of sector antenna units having a corresponding frequency converter is equal to the number of sector antenna units. The method according to claim 1, The splitter / combiner is configured to combine carrier signals associated with each of the plurality of sector antenna units to produce a combined signal in which all of the combined carrier signals are associated with different frequencies. Device used by The method according to claim 1, The splitter / combiner is configured to combine the received carrier signals associated with each of the plurality of sector antenna units to produce a composite signal in which some carrier signals to be combined are at different frequencies. Device for use in wireless base stations. The method according to claim 1, The frequency converter is: A first local oscillator (LO) providing a first LO frequency signal; A first mixer for frequency converting the carrier signal into an intermediate frequency (IF) signal using the first LO frequency signal; A narrowband IF filter for filtering the IF signal; A second local oscillator providing a second LO frequency signal corresponding to each frequency band; A second mixer for mixing the second LO frequency signal and the intermediate frequency signal to generate a frequency conversion output; And Apparatus for use in a multi-sector omni-radio base station, characterized in that it comprises a filter for filtering the frequency conversion output at each frequency. The method according to claim 1, The frequency converter is: A first local oscillator (LO) for providing a first LO frequency signal corresponding to each frequency; A first mixer for frequency converting the associated carrier signal using the first LO frequency signal; And And a narrowband filter for filtering the output of the first mixer at each frequency. 8. The method of claim 7, A feeder coupled to the splitter / combiner for transporting the composite signal, and And further comprising a base station unit coupled to the feeder for extracting respective carrier signals corresponding to the plurality of sector antenna units from the composite signal, the base station unit comprising one or more base station mixers, each base station mixer Is configured to frequency convert a corresponding one of each carrier signal associated with a different frequency to an intermediate frequency or baseband for further processing. 9. The method of claim 8, A first base station mixer is configured to receive a local oscillator signal to facilitate downconversion to the baseband or intermediate frequency of one of the subbands of the feeder, and a second base station mixer to 12. An apparatus for use in a multi-sector omni-radio base station, configured to receive another local oscillator signal to facilitate downconversion to the baseband or intermediate frequency of another. The method according to claim 1, At least one frequency converter is included in a corresponding one or more of said plurality of sector antenna units. The method according to claim 1, At least one frequency converter of each of the corresponding plurality of sector antenna units is included in the splitter / combiner. The method according to claim 1, And if there are a plurality of respective different frequency bands, the respective different frequencies are distributed over the available frequency bands. 13. The method of claim 12, Wherein each frequency band is distributed evenly over the usable frequency bands. The method according to claim 1, Wherein each antenna unit is a tower mounted amplifier (TMA) unit comprising a receive filter corresponding to an available bandwidth coupled to an amplifier for amplifying the received signal. . The method according to claim 1, Wherein said frequency converter and said splitter / combiner are combined into a single unit or are separate units. The method according to claim 1, A feeder coupled to the splitter / combiner for transporting the composite signal, and And a base station unit coupled to the feeder for extracting respective carrier signals from the synthesized signal. 17. The method of claim 16, The base station unit includes a transceiver having one or more mixers, each of the mixers configured to frequency convert each carrier signal to an intermediate frequency or base for further processing. Device used by The method according to claim 1, Wherein each sector comprises a first diversity antenna unit and a second diversity antenna unit. 19. The method of claim 18, The splitter / combiner combines a carrier signal associated with each of the first diversity antenna units to generate a first composite signal for communicating with the multi-sector omni-wireless base station, and And a second splitter / combiner for combining carrier signals associated with each of said second diversity antenna units to generate a second composite signal for communicating with said multi-sector omni-wireless base station. Device used in omni-wireless base stations. The method of claim 19, A first feeder coupled to a first splitter / combiner to transport the first composite signal; A second feeder coupled to a second splitter / combiner to transport the second composite signal; And A base station unit coupled to the first and second feeders for extracting respective carrier signals corresponding to a plurality of sector antenna units from the first and second composite signals, the base station unit comprising one or more base station mixers; Wherein each base station mixer is configured to frequency convert a corresponding one of each carrier signal associated with a different frequency into an intermediate frequency or baseband for further processing. Device. 19. The method of claim 18, The splitter / combiner is configured to combine carrier signals associated with each of the first and second diversity antenna units to generate a composite signal for communicating with the multi-sector omni-wireless base station -Devices used in wireless base stations. 22. The method of claim 21, A feeder coupled to the splitter / combiner for transporting the composite signal, and And further comprising a base station unit coupled to the feeder for extracting each received carrier signal corresponding to the plurality of sector antenna units from the composite signal, the base station unit comprising one or more base station mixers, each of And a base station mixer is configured to frequency convert a corresponding one of each received carrier signal associated with a different frequency to an intermediate frequency or baseband for further processing. The method according to claim 1, At least one narrowband filter is included in the splitter / combiner. A method for use in a multi-sector omni-radio base station comprising a plurality of sector antenna units each having an antenna and providing wireless communication coverage for a geographic site area divided into a plurality of sectors, the method comprising: Each of the plurality of sector antenna units transmits downlink transmissions and receives a carrier signal associated with a receive antenna frequency in an available frequency band to wirelessly communicate to a particular sector different from the sector covered by another of the plurality of sector antenna units. Providing coverage; Frequency converting the carrier signal received by one of the plurality of sector antenna units from the receive antenna frequency to a respective frequency different from the receive antenna frequency; Splitting a carrier signal received from a plurality of different sectors by a corresponding one of the plurality of sector antenna units to produce a composite signal comprising information received from the plurality of different sectors for communicating with the multi-sector omni-wireless base station Coupling in the uplink direction at the combiner; Receiving a downlink signal at full transmit power at the splitter / combiner; And Splitting the downlink signal at the splitter / combiner into a plurality of identical split signals transmitted by the plurality of sector antenna units, each of the split signals in full transmission of a received downlink signal Each portion of the power, each of the sector antenna units transmits each split signal at the same base station transmission frequency to each portion of the total transmit power, At least two of the carrier signals associated with the plurality of sector antenna units and combined in the splitter / combiner are at different frequencies. 25. The method of claim 24, And wherein the number of the plurality of sector antenna units for which the corresponding frequency conversion is performed is less than the number of the plurality of sector antenna units. 25. The method of claim 24, And the number of the plurality of sector antenna units for which the corresponding frequency conversion is performed is equal to the number of the plurality of sector antenna units. 25. The method of claim 24, The combining step comprises combining carrier signals associated with each of the plurality of sector antenna units to produce a composite signal in which all carrier signals being combined are at different frequencies. Method used by the base station. 25. The method of claim 24, The combining step includes combining carrier signals associated with each of the plurality of sector antenna units to produce a composite signal in which a portion of the combined carrier signals are at different frequencies. How to use in a wireless base station. 25. The method of claim 24, The frequency converting step is: Providing a first local oscillator (LO) frequency signal; Frequency converting the carrier signal into an intermediate frequency signal using the first LO frequency signal; Using a narrowband intermediate frequency to filter the intermediate frequency signal; Providing a second LO frequency signal corresponding to each frequency band; Mixing the second LO frequency signal and the filtered intermediate frequency signal to produce a frequency converted output; And Band-pass filtering the frequency converted output to the respective frequencies for use in a multi-sector omni-radio base station. 25. The method of claim 24, The frequency converting step is: Providing a first local oscillator (LO) frequency signal corresponding to each frequency; Frequency converting an associated carrier signal using the first LO frequency signal to produce a frequency converted output; And Narrowband filtering the frequency transformed output to the respective frequencies for use in a multi-sector omni-radio base station. 31. The method of claim 30, Transporting the synthesized signal to a base station unit via a feeder, and Extracting each carrier signal corresponding to the plurality of sector antenna units from the synthesized signal at the base station unit, wherein the extracting further processes one or more respective carrier signals associated with different frequencies. Frequency converting to an intermediate frequency or baseband for the use of the multisector omni-radio base station. 32. The method of claim 31, And at least two base station mixers in the base station unit receive different local oscillator signals. 25. The method of claim 24, And if there are a plurality of respective different frequencies, each different frequency is distributed over an available frequency band. 34. The method of claim 33, Wherein each frequency is distributed evenly over the usable frequency band. 25. The method of claim 24, Transporting the mixed signal to a base station unit via a feeder, and Extracting each carrier signal from the synthesized signal in the base station unit. 36. The method of claim 35, Wherein each sector comprises a first diversity antenna unit and a second diversity antenna unit. 37. The method of claim 36, The combining step is: Combining a carrier signal associated with each of said first diversity antenna units to generate a first composite signal for communicating from a first splitter / combiner to said multi-sector omni-radio base station, and Combining a carrier signal associated with each of said second diversity antenna units to generate a second composite signal for communicating from a second splitter / combiner to said multi-sector omni-wireless base station; Sector Omni-Wireless base station method. 39. The method of claim 37, Transporting the first composite signal through a first feeder; Transporting the second composite signal through a second feeder; And Extracting each carrier signal corresponding to the plurality of sector antenna units from the first composite signal and the second composite signal at the base station unit, wherein the extracting comprises one or more associated with different frequencies; Converting each carrier signal to an intermediate frequency or base frequency for further processing. 37. The method of claim 36, The combining step includes combining carrier signals associated with each of the first and second diversity antenna units to generate a composite signal for communicating with the multi-sector omni-wireless base station. Method used in sector omni-wireless base stations. 40. The method of claim 39, Transporting the composite signal through a feeder, and Extracting each carrier signal corresponding to the plurality of sector antenna units from the synthesized signal at the base station unit, wherein the extracting further processes one or more respective carrier signals associated with different frequencies. Frequency converting to an intermediate frequency or baseband for the use of the multisector omni-radio base station.

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